Industrial trucks



. Oct. 7, 1958 E *RQ RNQT '2,855,071

l INDUSTRIAL TRUCKS I 3 Sheets-Sheet l -IIIHIIUII Filed Hay 12, 1955 @im w *--nhw lill ,I :IIIII:

Oct. 7, 1958 A. E. R. ARNOT 2,855,071

INDUSTRIAL TRUCKS Oct. 7, 1958 A. E. R. ARNOT 2,855,071

INDUSTRIAL TRUCKS Filed May l2, 1955 5 Sheets-Sheet 3 United States Patent O Tlepresent: .inventioncomprises `improvements in -or .relating .to :industrial-trucks of the `type which lhave a mast comprisingtwo ltransversely `spaced mast side-membersunited by. a cross-piece, -a lcarriage mounted on the mast for up and down movement,-which carriage may carry fork-arms or other work engaging members or, in the case of a telescopic mast a mast extensible section.

One of the principal obstructions to the View between the sides of theV mast is the lifting gear for the carriage font-the `r'n`a'st,-whieh,-asit-must lift both; sides of the'cradle -orl-carria'geequallyis placed symmetrically 'and usually :comprises a vertical hydraulic-cylinder and ram and. Acliinsltherefrorn..running over-pulleyslon thelmast to the cradle. y

'Ihe present invention provides a construction in which the lifting parts are displaced to one side of the mast to afford a clear view and yet are capable of lifting both sides equally without imposing any bending or lateral stresses on the ram or associated parts.

According to the present invention a carriage lifting system for a truck of the type 'described comprises a substantially upright fluid-pressure cylinder disposed unsymmetrically so as to be close to one side-member of the mast, a lifting-ram within the cylinder and protruding above it crowned by a guide-carrying head, guides for chains, cables, or the like, transversely spaced apart on the head, and chains, cables 'or the like extending upwardly from a fixed retaining point or points over the said guides and then depending downwardly, one to an anchoring point on the carriage, and the other to a further guide under which it passes then over a final guide positioned adjacent the mast side-member furthest removed from the ram, to an anchoring point on the carriage.

ln a preferred construction an extensible mast section is mounted on the said carriage, a work-engaging member carrying carriage being mounted for up-and-down movement on the extensible section and operated by chains which are attached at one end of the said carriage and extend upwardly therefrom over a glide on the extensible section to an anchoring point on the xed mast. Preferably the guides comprise chain pulleys.

The following is a description by way of example of one embodiment of the invention as applied to fork lift trucks:

In the accompanying drawings,

Figure 1 is a side elevation of a truck in accordance with the invention;

Figure 2 is a front elevation of the same, and

Figure 3 is a plan.

The truck shown has a chassis which is made in two sections, a front section which consists of side straddle legs 11 having ground rollers 12 at their front ends and rigidly united to a cross-member 13 which supports a fixed mast 14; to this front section there is secured a rear section 15 of the truck which rests on wheels 16, 17, and comprises a casing 18 containing a power-driven steerable turntable mounting 19 for the wheel 16, which is operated by a steering wheel 20. The casing 18 and its con- 21' tents are located toone side-of therear sectionl 15 ofthe truck and beside it is a platform 21v above the wheel :'17 (which isa castor wheel `andthereforefollowsthe movements of the power-driven steering wheel 20) upon which the operator. can stand. The .platform21 is enclosed at the outerfside 'by a plate 22 and the front part'of'the rear section 15 of the truckis formed-by va-front-.plate 23 which extends between the platformfand the front part of the truck chassis ina vertical plane `and forms-the front part-'of thecasing 18. The back of the frontpart of the truck is formed by a plate 24'which is 'welded across the back of the mast 14 andsta'ndsup close in front of the plate 23. The `plates 23, 24, are united together-bya large central pivot bearing 25- (Figure. 3) Iwhichenables all the four wheels 12, 12, 16, 17, to' rest fequally upon the ground. Ther-.operator standing `ion the. platform 21 is to one side of the centre line of the truck rand -is able to steerit by the lwheel 20 and-to control the powermeans and brake by a control handle 26.

In 'front ofthe fixed mast 14 isa rising section of' the mast .27, and on the rising 'section-is a fork-carriage 28.

Thexed masthas atransverse shelf 36vwhich extends between its side-members, `and below-thefshelf `is aspace for a battery box-37-resting on .the bottom cross-member `13 already referred to.

The -xed mast 14 I comprises .two :upright -inwardly directed-channel-sectionside-members `29, 30 (seen in* secftion .in Figure) united at.the top-.by--a transverse crossmember 31. The rising mast-section 27 is of similar form with side channels 32, 33 and is mounted in front of the fixed mast with carriage-members 34, provided with rollers 35 which run within the inwardly directed ilanges of the fixed mast channel-section side members 29, 30. v

Within and slightly behind the ixed mast near one of the Side members 30 thereof is a hydraulic cylinder 40 resting on shelf 36, which is strengthened for the purpose. A hydraulic lifting ram 41 operates within the cylinder and extends just clear of the upper end thereof as shown in Figure 2, when the ram is in its lowermost position. Mounted on top of the ram 4I is a transversely extending head or chain pulley carrier 42 which is made up of two transversely extending plates welded to a central spacingmember 43 which member is attached to the end of the ram 41. Two pulleys 44, 45 are mounted on bearings between the plates, one on either side of the ram, so as to be capable of freely rotating. The transversely extending cross-member 31 on the fixed mast is of hollow plate construction and has'a pulley 46 mounted therein adjacent to and slightly below the ram head 42 (when the ram is in lowered position). Spaced from and at a higher level than this pulley, positioned within the said crossmember 31 at a point close to the side-member 29 remote from the hydraulic cylinder 40, is a further pulley 47. A pair of lifting chains 50, 51, are anchored at 48,A 49 to the top of the hydraulic cylinder 40 and pass upwardly on either side of the ram into the pulley carrying head 42 inside the pulleys 44, 45 and outwardly over them. The chain 50 nearest the mast upright 30, which is adjacent the hydraulic cylinder, then passes vertically downwardly close to that upright side member and is anchored to the carriage 34 at 52. The other chain 51 passes downwardly beneath the rst pulley 46 on the crossmember and then continues upwardly and transversely within the cross-member and over the pulley 47 furthest remote from the cylinder, and thereafter depends vertically downwardly to an anchoring point 53 on the carriage 34. The carriage 34 is so shaped at its rear that it will not foul the hydraulic cylinder 40 or chains 50, 51.

Mounted on the rising section 27 of the mast is the second carriage 28 already referred to which similarly runs on rollers 55 within the mast extensible section and which carries a pair of fork arms S6. This carriage is lifted on two chains S7, 58, one attached to each of the upper corners 59, 60 thereof. The chains extend upwardly within the extensible Section of the mast and pass over pulleys 61, 62 mounted on the top 63 of the section at the rear thereof. The chains 57, 58 then extend downwardly behind the extensible section and are anchored to the fixed mast at 64, 65.

In operation, uid pressure is admitted to the hydraulic cylinder 40 thus lifting the ram 41 and with it the extensible mast 27 on its carriage 34. The fork arm carrying carriage is lifted by its own chains 61, 62, at twice the rate of the extensible mast. It is to be understood, of course, that the chains may be replaced by cables or the like or that the lifting ram 41 may be pneumatically operated. Also that the hollow cross-member 31 may be positioned at a point on the mast other than its top, the same eect still being achieved.

What I claim is:

l. In a goods handling truck, the combination of a wheeled chassis, a generally vertical mast comprising two parallel spaced apart side members mounted on said chassis and a lixed transverse member extending between said side members at the upper ends thereof, said transverse member having first guide means on one end thereof adjacent one of said masts and second guide means positioned between said masts, a load carrying member mounted on and extending between said mast side members for vertical movement therealong, lifting means for said load carrying member comprising relatively movable cylinder and ram means mounted closely adjacent the other of said parallel side members and having a movable cross-head, and flexible means interconnecting each end of said cross-head and a side of said load carrying member, said exible means on the side of said crosshead adjacent said one mast extending ldownwardly around beneath said second guide, transversely therefrom to and upwardly around above said rst guide and then downwardly along said one mast to one side of load carrying member, and on the side of said cross-head adjacent said other mast extending downwardly along said other mast to the other side of said load carrying member, said first and second guide means being positioned on said xed transverse member providing parallel vertically extending ights of said exible means.

2. A truck as claimed in claim 1, wherein the loadcarrying member consists of a rising section of mast and a fork-carriage thereon.

3. A truck as claimed in claim 2, wherein the forkcarrage is slidable on the rising section of the mast and is supported on two exible lifting members one end of each of which is anchored to a part secured to the iixed mast and which pass over guides on the upper end of the rising mast and thence downwardly to the fork-carriage, to which they are secured.

lieierences Cited in the le of this patent UNITED STATES PATENTS 2,394,458 Lull Feb. 5, 1946 2,456,320 Repke Dec. 14, 1948 2,642,157 Milz June 16, 1953 2,678,746 Gibson May 18, 1954 2,770,324 Peterson Nov. 13, 1956 

